These generic functions must be defined for all stream classes.
stream-element-type Generic Function
stream-element-type stream
Summary: This existing Common Lisp function is made generic, but otherwise behaves the same. Class fundamental-character-stream provides a default method that returns character.
open-stream-p Generic Function
open-stream-p stream
Summary: This function is made generic. A default method is provided by class fundamental-stream that returns t if close has not been called on the stream.
close stream &key abort
Summary: The existing Common Lisp function close is redefined to be a generic function, but otherwise it behaves the same. The default method provided by the class fundamental-stream sets a flag used by open-stream-p. The value returned by close will be as specified by the X3J13 issue closed-stream-operations.
stream-pathname Generic Function
stream-pathname stream
stream-truename Generic Function
stream-truename stream
Summary: These are used to implement pathname and truename. There is no default method because these are not valid for all streams.
CLIM 2.0 User Guide - 01 Dec 2021 19:39:02